Bob Arum to Dana White: You Need Boxing to Save Your Ass

Another round in the Dana White vs. Bob Arum mega-feud ... this time, it's the legendary boxing promoter throwing major shade at White for his plans to get into boxing in 2018.

Arum tells TMZ Sports he welcomes the UFC honcho into the boxing community ... but then he fires this shot ...

"By coming in the business, he is really admitting that boxing is the more popular sport. And in order to keep his company alive, he has to go into the boxing business."

Of course, White hates Arum's guts -- and has been ripping him apart for years ... previously calling Bob the "biggest dirtbag in all of sports." So, no love lost here.

Still, Bob says he thinks Dana could be successful in the boxing business -- and gives him a real chance to make the Anthony Joshua vs. Deontay Wilder fight happen.

"If he puts up enough money, he certainly will land the fight," Arum said. "It's all a question of the money ... particularly in the heavyweight division."

You might remember -- Dana spoke with TMZ Sports last week, and told us Joshua was his #1 target ... and he's meeting with major players like Floyd Mayweather to help his cause.